Electric current rectifier



Filed Sept. 11. 1930 Patented Aug. 9, 1932 UmT-EnsrAT s OSKAR SEITZ, F BADEN, SWITZERLAND, ASSIGN OR TO AKTIE'NGESEILSCHAET BROWN,

BOVERI .& CIEL, OF BADEN, SWITZERLAND, A JOINT-STOCK COMPANY SVTITZER- AND ELECTRIC CURRENT RECTIFIER Application filed September 1-1, 1930, Serial No. 481,116, and in Switzerland August 1, 1929. I

This invention relates to improvements in electric current .rectifiers of the metallic vae p01 type and particularly to an improved construction of such rectifiers which will decrease the amount of metallic vapor continually present in the structure.

It is well-known that increased quantities of metallic vapor and, therefore, increased vapor density decreases the safety of operation of an electric current rectifier of the metallic vapor type due to the fact that the condensing capacity of the water-cooled walls of the rectifier is overtaxed. Globules of the metallic vapor are therefore likely to form,

vide a rectifier in which the anodes are ar ranged in a circle about a cooling member extending upwardly in the rectifier tank from the bottom thereof.

Another object of the invention is to provide an electric current rectifier in which the anodes are arranged in a circle and the cathode is in the form of an annulus arranged about a cooling member extending upwardly from the bottom of the rectifier tank and interiorly thereof.

Objects and advantages, other than those above set forth, will be apparent from the 1 following description when read in connection with the accompanying drawing in which Figure 1 is a vertical cross-sectional view through a rectifier embodying the present invention, and

Fig. 2 is a top plan View of the cooling Another object of the invention is to pro-' member formed according to the'present invention.

Referring more particularly to the drawing by characters of reference, the reference numeral 3- designat-es a tank which is doublewalled to provide a path for the circulation of a cooling medium therethrough and is, arranged to contain the devices, to be described hereinafter, maintaining an electric are through a medium, such as vaporized mercury, having a valve action on electric current The open top of the tank 3 is closed by a cover plate 4 having a plurality of anodes 6 extending therethrough in insulated relation therewith and an upward'extension 7 therefrom which extension is also made double-walled to permit the circulation of a cooling medium'therethrough and is hereinafter called the condensing dome. The bottom of the tank is formed in the shape of, a hollow truncated scone having its apex end extending downwardly and the aperture therethrough is closed by an annular closure plate 8 having an annular channel formed therein to receive an electric current conduc- 75 tive vaporizable material 9 having a valve action, when vaporized, on an electric current, which material serves as the cathode. The anodes 6 are surrounded by sleeves 11 depending from the insulator toward the bottom of the tank 3 and the closure plate 8 is connected with the tank by suitable non-conductive means 12 sealing the joint betweenthe tank I and the closure plate.

A substantially cylindrical, double-walled cooling member 13 having walls in the shape of a star is mounted on thevclosure plate 8 and is sealed thereon by suitable sealing means 14 in such manner as to close the aperture throughthe closure plate 8. The member 13 extends upwardly from the closure plate 8 as a cooling member, reentrant with respect to the casing 3, and beyond the open bottom ends of the anode sleeves 11 substantially into the plane ofthe anodes 6 and adjacent the bottom of the cooling dome 7. The cooling member is connected with and made a part of the path for the cooling medium circulating through the tank wall by the pipes 16 and 17. The interior of the por may flow upwardly in its natural paths from the cathode and the condensed mercury may return to the cathode without coming into contact with the arc flowing between an anode 6 and the cathode 9. The wallsof the cooling member 13 may be made in any other desirable form so long as sufficient cooling area is presented thereby;

It will be seen that the present invention provides a rectifier construction in which the quantity of vapor produced by the heating action of the are from the cathode is materially diminished by condensation thereofin the immediate vicinity of the cathode and that the'vapor so condensedmay return to the cathode without again coming into contact with the electric arc. The upper end of the cooling member extending beyond the open ends of the anode sleeves tendsparticularly to reduce the vapor density about the ends of the sleeves. The vapor in the space between the lower end of the condensing dome 7 and" the cooling member 13 is subjectto the cooling of both the dome and the cooling member which tends to create a partial vacuum therein whereby the vapor rising from the cathode is drawn away from the open ends of the anode sleeves. The total'result of all of the above effects is to decrease the vapor density therein to receive cathode material, said plate partially closing the aperture through the bottom of said tank, and a hollow double walled cooling member arranged to close the aperture in said plate and extending upwardly interiorly of said tank into substantially the plane determined by the ends of said anodes, said tank and said cooling member forming a path for the circulating of a cooling medium therethrough.

3. In an electric current rectifier, a casing, a circle of spaced anodes depending into said casing, an annular cathode of diameter less than the diameter of the circle formed by said anodes supported within said casing adjacent the bottom thereof, and a cooling member of cylindrical contour and diameter less than the diameter of said cathode reentrant through the bottom of said casing to a point substantially at the level of the said circle of anodes, the interior surfaces of said cooling member being open to the atmosphere. V

In testimony whereof I have hereunto subscribed my name this 28th day of August,

' OSKAR SEITZ.

in the anode sleeves thereby preventing con- 7 densationof the vapor on the anodes or sleeves and eliminating cathode spots which cause backfiring. 7 p p Although but one embodiment-of the present invention has been illustrated and described, it will be apparent to those skilled in the" art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

The invention claimedis: l c '1. In'an electric current rectifier" ofthe metallic vapor type, a double walled tank having an aperture through the bottom thereof, a plurality of anodes extending into saidtankthrough the covercplate thereof, an annular plate having'an annular channel therein to receive cathode material, said plate partially closing the aperture through the bottom of said tank, and; a hollow cooling member arranged to close the aperture in said plate and extending upwardly 'interiorly of said tankinto substantially the plane of said anodes, the interior surface of said cooling member being in contact with the atmosphere. 2. In an electric current rectifier of the metallic vapor type, a double walled t-ank having an aperture through the bottom thereof, a plurality, of anodes extending into i sa d tank through thecoverplatethereof, an annular plate having an annular channel 

